extern void add(char const*n,char const*p,char const*a);
extern int find_index_by_name(char const*n);
extern char const* find_phone_by_name(char const*n);
extern char const* find_address_by_name(char const*n);
extern void find_user_by_name(char const*n);
extern void print_top(void);
extern void print_all(void);
